Interconnected computer networks, such as the internet, are coupled together by routers. Such a computer network router is typically connected to two or more distinct networks. For a message sent from one network to another, destination network, the router receives the message, in the form of data packets, from one of the networks to which the router is connected, searches a database of routing information for determining to which of the connected networks the data packet should next be sent, so that the data packet can reach the destination network. The database of routing information can be quite large in networks, such as the internet, composed of many different interconnected networks. Therefore, searching the database may be relatively slow, in comparison with other aspects of data packet transmission, and a need consequently exists to speed up the searching.